Drexlerian nanotech

[stevebowers]

We already have artificial self-replicating systems available to us; they are called 'economies' and can't operate at the moment without human input. A mature, autonomous self-replicating system will involve a very large number of elements, from things as small as bacteria (often using actual modified or unmodified bacteria) to huge blast furnaces and rolling mills, if such things are necessary to produce the final product. In short - appropriate scale technology at each required level. I think that a lot of this will occur at the nanoscale, especially the control systems - but by no means all of it will.